US20080175303A1 - Thermocouple Assembly And Method Of Use - Google Patents

Thermocouple Assembly And Method Of Use Download PDF

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Publication number
US20080175303A1
US20080175303A1 US11/793,877 US79387705A US2008175303A1 US 20080175303 A1 US20080175303 A1 US 20080175303A1 US 79387705 A US79387705 A US 79387705A US 2008175303 A1 US2008175303 A1 US 2008175303A1
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United States
Prior art keywords
thermocouple
temperature
assembly according
junction
thermocouple assembly
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/793,877
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English (en)
Inventor
Bernard Robbins
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vesuvius Crucible Co
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Vesuvius Crucible Co
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Assigned to VESUVIUS CRUCIBLE COMPANY reassignment VESUVIUS CRUCIBLE COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ROBBINS, BERNARD, RUSH, DAVID, FARRELL, DAVID, VAN DER MAAT, PAUL
Publication of US20080175303A1 publication Critical patent/US20080175303A1/en
Abandoned legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples
    • G01K7/04—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples the object to be measured not forming one of the thermoelectric materials
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
    • H10N10/80—Constructional details
    • H10N10/85—Thermoelectric active materials

Definitions

  • the present invention concerns a thermocouple assembly for the measurement of the temperature of a molten phase (or other high temperature applications) and to a method for the measurement of the temperature of a molten phase (or other high temperature applications) using the said thermocouple assembly.
  • thermocouples constituted of metals are known and have been widely used for decades. Unfortunately, the metals used for these thermocouples have a tendency to oxidize or to be chemically attacked during use so that their accuracy is not guaranteed over extended periods. It has already been described that certain non-metallic materials, for example ceramics, may also produce an electromotive force in relation to their temperature. Ceramics do not suffer the above disadvantages.
  • thermocouple assemblies for the measurement of the temperature of a molten phase and other high temperature applications. These thermocouple assemblies consist of first and second ceramic elements contacting each other at a junction wherein one of the ceramic elements is urged against the other.
  • cold ends designates the ends of the first and second ceramic elements which are opposite to their junction (hot junction).
  • thermocouple assembly for the measurement of a temperature comprising first and second ceramic elements contacting each other at a first junction and forming thereby a first thermocouple
  • this objective can be reached when the assembly also comprises a second thermocouple formed of two different conducting elements (generally metallic conductors) contacting each other at a second junction located on the first ceramic element and a third thermocouple formed of two different conducting elements (generally metallic conductors) contacting each other at a third junction located on the second ceramic element, wherein both positive legs or both negative legs of the second and third thermocouples are connected to a first measuring device, while both legs of the second and third thermocouple are connected respectively to a second and third measuring device.
  • the inventors have indeed realised that it is impossible to accurately compensate by electronic means only the electromotive force generated at these cold junctions for a broad range of temperatures and have therefore decided to measure or calculate them exactly and then add or subtract these electromotive forces to calculate the true electromotive force at the hot junction.
  • the first measuring device is an electromotive force readout meter while the second and third measuring devices are thermocouple temperature measuring devices.
  • the electromotive forces generated at said cold junctions can be calculated by comparing the measured temperature values to experimental data (calibration curve) or theoretical data (polynomial curve).
  • the first, second and third measuring devices are electromotive force readout meters.
  • the second and third electromotive force readout meters comprise compensating means (for example electronic circuits) for these electromotive forces.
  • the conducting elements of both thermocouples as well as the connectors of their respective electromotive force readout meters are metallic conductors so that conventional cold junction compensating means can be used.
  • the first and second ceramic elements are made from materials selected from the group consisting of silicon carbide, alumina-graphite based compositions, titanium nitride, molybdenum disilicide, boron carbide, titanium dioxide, carbon and stabilized zirconia alone or in admixture.
  • the first ceramic element comprises molybdenum disilicide and the second ceramic element comprises silicon carbide or titanium nitride.
  • the first ceramic element comprises silicon carbide or titanium nitride and the second ceramic element comprises an alumina-graphite based composition.
  • alumina-graphite based compositions comprise generally 40-70 wt. % alumina, 20-40 wt. % graphite, 2-10 wt. % carbon based binder and the remainder of other refractory oxides such as magnesia, zirconia, silica, etc, the compositions disclosed in U.S. Pat. No. 4,721,533 are suitable to this end.
  • the first ceramic element forms an inner leg and the second ceramic element forms an outer sheath.
  • the second ceramic element protects the first ceramic element from attacks by the molten phase.
  • the second ceramic element is generally selected to be suitable to resist the molten phase attacks for a certain time, very suitable materials in this case are the alumina-graphite based compositions.
  • the assembly preferably further comprises an electrically insulating sleeve (preferably constituted of alumina) around the inner leg. This provides electrical insulation and helps to provide rod retention and cushioning from vibration.
  • the thermocouple assembly can itself be engaged into a ceramic protective sleeve, for example as described in U.S. Pat. No. 4,721,533.
  • a ceramic protective sleeve for example as described in U.S. Pat. No. 4,721,533.
  • Alumina based coatings are particularly suitable for such applications.
  • the sleeve itself can be formed as a part of a conventional casting piece such as a stopper, a submerged entry nozzle, an inner nozzle, a refractory plate, etc. as disclosed in GB-A-2263427.
  • the invention relates to a method for the measurement of a temperature comprising
  • thermocouple assembly a thermocouple assembly according to the present invention into a hot environment, the first junction being positioned at or near the point the temperature of which has to be measured, b) calculating or measuring the values of the first, second and third electromotive force with the first, second and third measuring devices; c) calculating the true electromotive force generated at the first (hot) junction by adding or subtracting the calculated or measured electromotive forces generated at the cold junctions; d) converting the true electromotive force calculated in step c) into a temperature.
  • the total electromotive force read on the meter will be equal to the electromotive force generated at the first (hot) junction plus the electromotive force generated at the cold end of the first ceramic element (as calculated or measured using the second measuring device) minus the electromotive force generated at the cold end of the second ceramic element (as calculated or measured using the third measuring device).
  • the electromotive force generated at the first (hot) junction can thereby be easily assessed and converted into a temperature, for example by comparing this value with a calibration curve or a polynomial expression.
  • steps b) to d) will provide a continuous measurement of the temperature.
  • FIG. 1 depicts a schematic thermocouple assembly according to the invention
  • FIG. 2 is a diagram showing the temperature determined with the thermocouple assembly of FIG. 1 using the above described method.
  • FIG. 1 schematically shows thus a thermocouple assembly for the measurement of the temperature of a molten phase according to the invention. It is constituted of first and second ceramic elements ( 1 , 2 ) contacting each other at a first junction ( 3 ) and forming thereby a first thermocouple. In use, the junction ( 3 ) is positioned at or under the level of the molten phase.
  • a second thermocouple formed of two different conducting elements ( 4 , 5 ), preferably metallic conductors, contacting each other at a second junction ( 6 ) is located on the first ceramic element ( 1 ) (preferably around the cold end of the first ceramic element ( 1 )).
  • a third thermocouple formed of two differing conducting elements ( 7 , 8 ), preferably metallic conductors, contacting each other at a third junction ( 9 ) is located on the second ceramic element ( 2 ), (preferably around the cold end of the second ceramic element ( 2 )).
  • Both positive legs ( 4 , 7 ) or both negative legs ( 5 , 8 ) of the second and third thermocouples are connected to a first measuring device ( 10 ) (for example, an electromotive force readout meter).
  • Both legs ( 4 , 5 ; 7 , 8 ) of the second and third thermocouple are connected respectively to a second and third measuring device ( 11 , 12 ) (for example thermocouple temperature measuring devices).
  • the electromotive forces generated at the cold ends are precisely measured and can be taken into account when determining the true electromotive force generated at the hot junction ( 3 ).
  • the electromotive force generated at the hot junction can thereby be easily assessed and converted into a temperature, for example by comparing this value with a calibration curve or a polynomial expression.
  • such an installation can be achieved very simply by using both positive legs ( 4 , 7 ) or both negative legs ( 5 , 8 ) of the second and third thermocouples which are connected to a first electromotive force readout meter ( 10 ).
  • FIG. 2 Visible in FIG. 2 is a curve depicting the temperature measured continuously with the thermocouple assembly according to the invention (continuous line) in a tundish used for the continuous casting of molten steel versus the casting time.
  • the thermocouple assembly was inserted into an alumina-graphite protective sleeve as described in U.S. Pat. No. 4,721,533 and located near the stopper rod controlling the molten steel flow exiting from the tundish.
  • the response time of the thermocouple assembly was considered excellent.
  • the temperature of the tundish was about 1450° C.; this coincides with the end of the first ladle.
  • thermocouple assembly of the type ACCUMETRIX sold by VESUVIUS USA CORPORATION as disclosed in U.S. Pat. No. 4,721,533 located at the opposite side of the tundish.
  • the temperatures measured with the ACCUMETRIX sensor are depicted as triangles on FIG. 2 . It can be seen that the temperatures measured with both systems correspond perfectly all along the casting operations. After use, the thermocouple assembly according to the invention was inspected and no damage was observed.
US11/793,877 2004-12-21 2005-12-20 Thermocouple Assembly And Method Of Use Abandoned US20080175303A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP04447285.0 2004-12-21
EP04447285A EP1677087A1 (fr) 2004-12-21 2004-12-21 Ensemble de thermocouples et un procédé d'utilisation
PCT/EP2005/013693 WO2006066862A2 (fr) 2004-12-21 2005-12-20 Ensemble thermocouple et son procede d'utilisation

Publications (1)

Publication Number Publication Date
US20080175303A1 true US20080175303A1 (en) 2008-07-24

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US11/793,877 Abandoned US20080175303A1 (en) 2004-12-21 2005-12-20 Thermocouple Assembly And Method Of Use

Country Status (8)

Country Link
US (1) US20080175303A1 (fr)
EP (2) EP1677087A1 (fr)
KR (1) KR20070090028A (fr)
CN (1) CN101084420A (fr)
CA (1) CA2590298A1 (fr)
TW (1) TW200630600A (fr)
WO (1) WO2006066862A2 (fr)
ZA (1) ZA200705773B (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070029303A1 (en) * 2005-07-21 2007-02-08 Weston Aerospace Limited Ceramic thermocouple
US8047712B1 (en) * 2007-07-26 2011-11-01 Lockheed Martin Corporation Method and apparatus for predicting steady state temperature of solid state devices
CN102455224A (zh) * 2010-10-28 2012-05-16 康宁股份有限公司 带有沿横向轴线分隔开的两个接头的热电偶和方法
CN106768438A (zh) * 2016-11-18 2017-05-31 中国计量大学 一种新型热电偶测量端及其制作方法
DE102020203166A1 (de) 2020-03-12 2021-09-16 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein Sensoraufbau zur Bestimmung hoher Temperaturen und Verfahren zur Herstellung des Sensoraufbaus

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009050433B3 (de) * 2009-10-22 2010-10-07 Abb Ag Vorrichtung und Verfahren zur Kalibrierung von Temperaturfühlern
CN102095513B (zh) * 2011-01-27 2012-10-10 洛阳市西格马仪器制造有限公司 一种硼化物复合陶瓷温度传感器
DE102012003614B3 (de) * 2012-02-23 2013-05-29 Testo Ag Temperaturmessgerät, Temperaturmessgerät-Set und Verfahren zur Konfiguration eines mit einem Thermoelement betreibbaren Temperaturmessgeräts
CN102944321B (zh) * 2012-12-07 2014-07-16 重庆材料研究院 用于测量微距离温差的高精度厚膜型热电偶组的制备方法
CN103105241A (zh) * 2013-01-30 2013-05-15 上海安可泰环保科技有限公司 一种高电压环境下应用的热敏陶瓷温度传感装置
CN105716733B (zh) * 2016-01-29 2018-07-17 东南大学 一种火电机组套管式热电偶温度测量的动态校正方法
EP3486626A4 (fr) * 2016-07-15 2020-03-11 Miyagawa Kasei Industry Co., Ltd. Thermocouple

Citations (11)

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US2981775A (en) * 1958-11-12 1961-04-25 Steatite Res Corp Oxide thermocouple device
US3085125A (en) * 1961-10-02 1963-04-09 Gen Motors Corp Thermocouple
US3757206A (en) * 1970-04-09 1973-09-04 Qualitats Und Edelstahl Kom Ve Differential thermolements
US4721533A (en) * 1986-08-01 1988-01-26 System Planning Corporation Protective structure for an immersion pyrometer
US5356485A (en) * 1992-04-29 1994-10-18 The United States Of America As Represented By The Secretary Of Commerce Intermetallic thermocouples
US5713668A (en) * 1996-08-23 1998-02-03 Accutru International Corporation Self-verifying temperature sensor
US6072165A (en) * 1999-07-01 2000-06-06 Thermo-Stone Usa, Llc Thin film metal/metal oxide thermocouple
US6239351B1 (en) * 1993-07-01 2001-05-29 Hoskins Manufacturing Company Multi-wire self-diagnostic thermocouple
US20040161014A1 (en) * 2002-07-23 2004-08-19 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) Temperature measuring apparatus of high melting point metal carbide-carbon system material thermocouple type, and method for producing the apparatus
US6872879B1 (en) * 2001-03-16 2005-03-29 Edouard Serras Thermoelectric generator
US7029173B2 (en) * 2000-06-21 2006-04-18 Robert Bosch Gmbh Thermoelectric component

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Publication number Priority date Publication date Assignee Title
GB815047A (en) * 1957-09-10 1959-06-17 Max Planck Inst Eisenforschung Improvements relating to thermocouples
GB2288908B (en) * 1994-04-27 1997-08-20 Rowan Technologies Ltd Ceramic thermocouple
JP2003344169A (ja) * 2002-05-22 2003-12-03 Shin Etsu Chem Co Ltd 熱電対保護管

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2981775A (en) * 1958-11-12 1961-04-25 Steatite Res Corp Oxide thermocouple device
US3085125A (en) * 1961-10-02 1963-04-09 Gen Motors Corp Thermocouple
US3757206A (en) * 1970-04-09 1973-09-04 Qualitats Und Edelstahl Kom Ve Differential thermolements
US4721533A (en) * 1986-08-01 1988-01-26 System Planning Corporation Protective structure for an immersion pyrometer
US5356485A (en) * 1992-04-29 1994-10-18 The United States Of America As Represented By The Secretary Of Commerce Intermetallic thermocouples
US6239351B1 (en) * 1993-07-01 2001-05-29 Hoskins Manufacturing Company Multi-wire self-diagnostic thermocouple
US5713668A (en) * 1996-08-23 1998-02-03 Accutru International Corporation Self-verifying temperature sensor
US5887978A (en) * 1996-08-23 1999-03-30 Accutru International Corporation Self-verifying temperature sensor
US6072165A (en) * 1999-07-01 2000-06-06 Thermo-Stone Usa, Llc Thin film metal/metal oxide thermocouple
US7029173B2 (en) * 2000-06-21 2006-04-18 Robert Bosch Gmbh Thermoelectric component
US6872879B1 (en) * 2001-03-16 2005-03-29 Edouard Serras Thermoelectric generator
US20040161014A1 (en) * 2002-07-23 2004-08-19 Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) Temperature measuring apparatus of high melting point metal carbide-carbon system material thermocouple type, and method for producing the apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070029303A1 (en) * 2005-07-21 2007-02-08 Weston Aerospace Limited Ceramic thermocouple
US7771116B2 (en) * 2005-07-21 2010-08-10 Weston Aerospace Limited Ceramic thermocouple
US8047712B1 (en) * 2007-07-26 2011-11-01 Lockheed Martin Corporation Method and apparatus for predicting steady state temperature of solid state devices
CN102455224A (zh) * 2010-10-28 2012-05-16 康宁股份有限公司 带有沿横向轴线分隔开的两个接头的热电偶和方法
CN106768438A (zh) * 2016-11-18 2017-05-31 中国计量大学 一种新型热电偶测量端及其制作方法
DE102020203166A1 (de) 2020-03-12 2021-09-16 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein Sensoraufbau zur Bestimmung hoher Temperaturen und Verfahren zur Herstellung des Sensoraufbaus

Also Published As

Publication number Publication date
EP1831660A2 (fr) 2007-09-12
WO2006066862A2 (fr) 2006-06-29
TW200630600A (en) 2006-09-01
ZA200705773B (en) 2009-01-28
WO2006066862A3 (fr) 2006-10-26
CN101084420A (zh) 2007-12-05
KR20070090028A (ko) 2007-09-04
EP1677087A1 (fr) 2006-07-05
CA2590298A1 (fr) 2006-06-29

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Owner name: VESUVIUS CRUCIBLE COMPANY, DELAWARE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ROBBINS, BERNARD;FARRELL, DAVID;RUSH, DAVID;AND OTHERS;REEL/FRAME:019535/0442;SIGNING DATES FROM 20070611 TO 20070612

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